1. Technical Field
The technical field relates generally to surgical suturing instrumentation and, more particularly, to surgical suturing apparatus having angled jaw structure for use in heart valve replacement surgery and to disposable loading units containing surgical needles for use with the surgical suturing apparatus.
2. Background of Related Art
The diagnosis and treatment of coronary disease and related conditions often requires repair or replacement of the valves located within the heart. Various factors, such as, for example, calcification, may result in the mitrial or aortic valves becoming impaired or functionally inoperative requiring replacement. Where replacement of a heart valve is indicated, in general, the dysfunctional valve is cut out and replaced with either an artificial, synthetic heart valve or a harvested porcine heart valve. The replacement valve is typically sutured in place of the original valve.
It is common to access the heart in a patient's thoracic cavity by making a longitudinal incision in the chest. This procedure, referred to as a median sternotomy includes cutting through the sternum and forcing the two opposing halves of the rib cage to be spread apart allowing access to the thoracic cavity and thus the heart.
Once access to the thoracic cavity has been achieved, surgery on the heart to effect valve replacement may be performed. During some procedures, the heart beat is arrested by infusion of a cardioplegic fluid, such as potassium chloride (kcl), to paralyze the myocardium while blood flow circulation is maintained through known heart bypass techniques. Alternatively, the heart is allowed to beat to maintain circulation, while a localized area of the heart, on which surgery is to be performed, is locally immobilized.
The heart is incised and the defective valve is cut away leaving a surrounding area of locally tougher tissue. Known heart valve replacement techniques typically include individually passing individual sutures through the tough tissue to form an array of sutures. Free ends of the sutures are extended out of the thoracic cavity and laid, spaced apart, on the patient's body. The free ends of the sutures are then individually threaded through an edge around the circumference of the replacement valve or a supporting cuff. Once all sutures have been run through the valve, all the sutures are pulled up taut and the valve is slid or "parachuted" down into place adjacent the tough tissue. Thereafter, the replacement valve is secured in place using the sutures.
While the above described procedures are sufficient to successfully install sutures within heart valve tissue, and position an artificial heart valve within the heart and subsequently suture the valve to the tissue, they are particularly time consuming. Therefore, a need exists for apparatus and procedures of quickly and efficiently suturing artificial heart valves within the heart.